Americans have kettles, people. Yes, we drink both hot and iced tea, and it's very normal all over the US (I have lived in all areas of the country), but drinking any kind of tea isn't nearly as popular as drinking coffee. No, we don't put cream or milk or whatever into our tea. We definitely don't say "cuppa" or (apparently?) use tea references in relation to time.
We do not use the word "mum." We also don't say "He was sat down" (Why are you using the passive voice instead of the active voice "He was sitting down" or "He sat down"?). We don't say "I have done in the past" (have done WHAT in the past?? Where is the direct object???). We don't say "I went to hers" or the myriad other grammatical mysteries that I find fascinating as hell. (I'm a grammar teacher, having learned American English grammar at high levels by studying Latin, so it DOES actually fascinate me. No shade.)
Non-idiot Americans understand quite well that this is a primarily British-based site (English-based? UK-based?) and that our references regarding politics, laws, culture, etc. have no basis here, which means giving advice based on US experience is ridiculous. (But there are plenty of idiots out there, American and otherwise, so you'll inevitably get clueless fools.) As such, I don't give advice about anything other than relationship stuff, which I gather is quite similar all over the planet.
Americans can ABSOLUTELY be culture-centric. I loathe quite a bit about the American culture (e.g. reality tv, Britney Spears and pop "artists" of that ilk, fast food), so it's disappointing that so much of the world has spent so much money on it that their companies want to keep dishing it out to their citizens, but, hey, it's their money. I think of America as an annoying teenager (given the relative recency of the culture) who thinks the entire world revolves around them and that they know everything. Do with it what you normally do with those kinds of teenagers.
But, yeah, I think you guys might consider replacing "Americans" with "Jews" or "blacks" or "fat people" and see how legit these comments about Americans still are.